Conventionally, as an illumination lamp installed outdoors such as in a park or along a street, there is known an illumination lamp in which a lamp fitting is arranged in an upper portion of a support to illuminate a lower place and which illuminates a predetermined area below the lamp fitting. In an area, a place or the like where electric power is difficult to obtain, there is also known an illumination lamp which includes an electric power generation member, such as a solar panel or a wind power unit, that utilizes natural energy to generate electric power and a storage battery.
When a lamp fitting needs to be lit to widely illuminate the ground, light is diffused through a protective cover arranged in the front surface of a light-emitting portion included in the lamp fitting, a plurality of light-emitting portions that conduct illumination in predetermined directions are fitted so as to conduct illumination in different directions or another method is used. Hence, for example, a plurality of lamp fittings provided with a light-emitting portion having a large number of light-emitting members (for example, LEDs) that conduct illumination in predetermined directions are prepared, and the lamp fittings are attached with the directions of the illumination included at angles outside the predetermined angle, and thus it is possible to obliquely downwardly illuminate a wide area to produce a wide illumination area.
As a lamp fitting that has a large number of light-emitting members within a casing and that conducts illumination in a predetermined direction, there is a lamp fitting 1D, as shown in FIG. 7, in which a light-emitting portion 2 having a large number of light-emitting members 21 is attached to a flat attachment surface 11D of the casing 10D and in which a protective cover 3 is fitted to its front surface in the direction of illumination. The lamp fittings 1D described above are used; specifically, as shown in FIG. 8, an illumination lamp STB in which two lamp fittings 1D are attached to an upper portion of a support while inclined at predetermined angles is used, and thus different illumination areas H1 are produced. It is therefore possible to illuminate a wide illumination area HA.
With an illumination lamp 1C in which, as shown in FIG. 6, two attachment members 7 having inclined light-emitting portion attachment surfaces are provided on a flat attachment surface 11C of a casing 10C opposite each other such that their light-emitting portions 2 (2A and 2B) face outward, it is possible to illuminate a wide area.
Furthermore, an attempt to attach a large number of light-emitting members to a curved-shaped holder is made to extend an illumination area; there have been disclosed street lamps and illumination lamps in which a large number of light-emitting members are attached to a cylindrical attachment holder that is previously divided into two halves so as to extend an illumination area. (for example, see patent document 1).